Skiving machine



July 10, 1962 Filed Feb. 23. 1960 2/6 FIG.7

E. H. BECK 3,043,126

SKIVING MACHINE l1 Sheets-Sheet 1 11 Sheets-Sheet 2 July 10, 1962 E. H. BECK SKIVING MACHINE Filed Feb. 23. 1960 July 10, 1962 E. H. BECK 3,043,126

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amaze Patented July 10, 1962 nice 3,643,126 SEWING MACHINE Edwin H. Beck, Lemay, Mo, assignor to Manufacturers Supplies Company, St. Louis, Mo., a corporation Filed Feb. 23, 1960, Scr. No. 10,113 29 Claims. (Cl. 69-9.5)

This invention concerns skiving machines, and more particularly skiving machines of the bell knife type for making various contours of skives on a single piece of leather and discloses improvements in skiving machines such as described and illustrated in my co-pending application for Skiving Machine, Serial No. 896,062, filed April 13, 1959, now abandoned, of which this application is a continuation in part.

Skiving machines of the bell knife type operate by feeding the leather blank to be skived against a rotating knife. The depth and angularity of the skive is determined by a presser foot which guides the blank into the knife. it has been customary in the past to use several machines for making various types of skives, the leather blanks being moved from one machine to the next between operations, usually in bundles. This procedure involved a considerable amount of delay, coupled with unnecessary handling and bundling of the leather blanks. In addition, in small factories, such a setup required an unnecessary duplication of machinery. In order to overcome these difficulties, it has been proposed to make the presser foot adjustable by using a treadle-controlled adjusting mechanism which moves the presser foot into various positions corresponding to the various types of skives to be made. In this manner, the operator was able to change the angularity of skive at will and thus make three different angularities of skive on the same piece of leather without moving it away from the machine. Such machines are described in my Patents Nos. 2,753,709 and Re. 24,142.

However, the adjustable single foot machine is not entirely satisfactory for the following reason: The three most common types of skive required in the shoe industry are a long, relatively flat bevel, a short steep bevel, and a grooved bevel. The first two skives can be easily made by merely altering the slope of the same presser foot with respect to the knife, but the grooved type of skive requires a different presser foot e.g. one having a grooving finger. In a leather-working factory when both the grooved and the ungrooved types of skives must be made on the same work, it has been customary to provide two machines with the different styles of presser feet rather than to waste time in making frequent exchanges of the presser foot on a single machine. With respect to the un grooved bevel, l have found that for a large majority of uses, a compromise bevel can be substituted for both the short steep bevel and the long relatively flat bevel. It is hence an object of the invention to provide a skiving machine having two presser feet which can be instantaneously placed into and retracted from a working po sition.

-t is a further object of the invention to provide such a skiving machine in which accurate and positive positioning of the respective presser feet is assured in each operation.

It is a further object of the invention to provide such a skiving machine in which provision is made for preventing inadvertent adjustment of a presser foot to a position where it would contact a moving part of the machine and be damaged thereby.

[It is a still further object of the invention to provide such a skiving machine in which the assembly of presser feet and their immediate mechanism can be easily exchanged by unskilled personnel without disturbing the adjustment of the mechanism.

It is still another object of the invention to provide a skiving machine which can be tilted out of working position for access to the mechanisms on the underside of the working plate without requiring disconnection of the treadle-controlled operating bar.

It is another object of the invention to provide one guide means for the edge of the leather blank when one presser foot is in use and another when the other foot is in use.

These and other advantages will be apparent from the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a perspective left-front view of the machine as it would appear to the operator;

FIG. 2a and FIG. 2b is a view taken on the line 2-2 of PEG. 1 showing the left side of the head in vertical elevation on one sheet of drawings and a vertical section through the base of the machine on following sheet of drawings;

FIG. 3 is a vertical section along line 3-3 of FIG. 2;

FIG. 4 is a plan View of the head portion of my machine;

FIG. 5 is a vertical section along line 55 of FIG. 4;

FIG. 6 is a vertical section through the base taken along line 6-6 of FIG. 3;

FIG. 7 is a perspective left-hand view of the grooving foot in the retracted position;

FIG. 8 is a right-hand perspective view of the grooving foot in the operating position;

FIG. 9 is a perspective, partly cut-away view of the guide arm locking mechanism;

FIG. 10 is a detail vertical section of the grooving foot and knife showing how a grooved skive is made;

FIG. 11 is a perspective view of a beveled skive made on my machine;

FIG. '12 is a like view of a grooved skive;

FIG. 13 is a perspective view of an optional selective guiding device;

FIG. 14 is a front elevation on an enlarged scale illustrating the mounting of the backing plate for the selflocking mechanism on the head of the machine;

FIG. 15 is an elevational view on an enlarged scale of the back side of the backing plate for the self-locking mechanism shown in FIG. 14;

FIG. 16 is an exploded view in perspective of the parts of the self-locking mechanism shown on an enlarged scale wherein the front side of the hacking plate and trigger member are shown on one side and the back side of the control arm and grippers are shown on the left side;

FIG. 17 is a top View showing a cross-section of the self-locking mechanism taken on a horizontal plane extending through the control arm pivot with the parts in an intermediate position;

FIGS. 18 and 19 are operational schematic illustrations of the operations of the self-locking mechanism shbwn in FIGS. 14 through 17;

FIG. 20 is an elevational view of the left side of the head mechanism showing a modification of this invention;

FIG. 21 is a detail view in elevation of the subassembly of elements forming the forward or right presser foot of the machine shown in FIG. 20;

FIG. 22 is a view in perspective illustrating the back side of the fixed guide of the presser foot mechanism shown in FIG. 21;

FIG. 23 is a View in perspective of the slide carrier which fits in the fixed guide for the front presser foot;

FIG. 24 is a perspective view of the front side of the rear presser foot and its holder;

terfere with each others movement.

FIG. 25 is a perspective view of the rear side of the fixed guide for the back presser foot;

FIG. 26 is a perspective view of the rear side of the slide carrierfor the back presser foot; and

FIG. 27 is a perspective view of the back side of the back presser foot.

'Basically, a skiving machine consists of a work surface underneath which are mounted a bell-shaped rotary knife and a grooved feed roll which is driven concurrently with the knife and moves apiece of leather deposited thereon against the knife. A presser foot is arranged immediately above the crest of the feed roll so as to direct the leather blank toward the knife at the desired angle. Since the depth of the cut is determined by the distance between the bottom of the presser foot and the knife, it will readily be seen that the angularity and contour of the cut is governed by the slope and contour of the presser foot with respect to the knife. In order to obtain a grooved cut in the leather, a grooving finger protrudes from the underside of the presser foot so as to force the leather blank closer against the knife at one area than at the adjacent areas.

In order to move the presser feet of my machine into and out of operating position, the presser feet are mounted on positioning slides which are movably supported in appropriate guides, the positioning slides being arranged at an angle to one another so the presser feet will not in- The positioning slides are moved angularly up and down in their guides by appropriatemechanism actuated by the operator. The slides are'so interconnected and their operating mechanism so arranged as to avoid collision of the presser feet as they are moved into and out of operating position. This particular arrangement of operating mechanism shown in the drawings has the advantage of allowing the use of relatively short slides which permit keeping the size of the slide mechanism assembly within reasonable limits. In addition, my construction permits full retraction of one foot before the other one starts to move out. The distance which each slide can be moved toward the feed roll is limited by an adjustable stop member. A second stop member is also provided on each slide so as to render inefiective any adjustment of the first stop means which would allow carrying the presser foot into contact with the feed roll.'

' As stated above the projection and retraction of the presser feet is, in this case, under the manual control of the operator. It is contemplated that this manual control can bedirect, or indirect,.through a suitable power mechanism, and a linkage has been shown which' is adapted for either manual or power operation, it being understood that the type, or kind, of power operation is immaterial to the i'nvention. Thus for purposes of illustration, the operated control is here illustrated as a manually operated linkage, preferably by a two positioned foot pedal which is connected by a suitable linkage with the presser foot operating mechanism. interposed in this mechanism is a self-locking device, which can be termed a self-locking drive connection in that it permits movements of the foot pedal to operate the presser feet, but prevents any force on the presser foot from moving the foot pedal. This 4 extreme position to the other extreme position, or is moved only far enough to approach an extreme position, will determine the depth of the skive. This self-locking drive connection has all the attributes of a remote control of the power operated type, since the pressure under the presser foot cannot be transmitted back to the manual controlled pedal. i

In order to facilitate service of the mechanism below the working surface, the entire machine can be swung upward and backward around a pair of hinges by which its rear edge is mounted on the table. 7 In order to avoid having to disconnect the operating rod each time the machine is so serviced, with the consequent danger of misadjusting the operating rod when it is re-connected, the operating rod according to the invention has a bowed-out portion adapted to clear all parts of the machine when the. machine is tilted back, and it is hinged near the table surface so as to be able to tilt backwards with the machine.

A mounting plate carries the mechanism which immediately operates the slides. The combination of the vmounting plate and the mechanism, carried thereby is hereinafter referred to as the head or head assembly. The mounting plate is attached by screws to a stationary supporting plate welded to a fixed arm on the machine. Adjustable set screws are provided in the supporting plate for adjusting the position of the mounting plate with respect to the supporting plate. Thus, the position of the mounting plate, and hence the position of the presser feet with respect to the knife and feed roll, can be adjusted once and for all by the machine builder. Once this adjustment has been made, unskilled personnel can .readily interchange heads by merely removing the holding screws,

, lifting off the head, substituting another head, and replacself-locking mechanism relieves the operator of strain during operation of the mechanism. No matter how tough the leather to be cut, it is unnecessary for the operator to continuously exert pedal pressure to hold the presser foot, or either one, in a fixed position with respect to the feed roll and knife. The operator, therefore, controls the presser feet through ,a self-locking driveconnection, which relieves the operator of the duty of holding the pedal control in a fixed position. On the other hand, this selflocking drive connection is such'that lost motion is negligible, so that accurate control is provided. This means that the pedal control is so precise that it may actually be used to control the depth of the skive in an extremely precise manner. Whether the pedal is forced from one ing and tightening the holding screws.

Experience has shown that in the operation of the machine with an ordinary beveling type of presser foot, it is preferable to have a guide immediately adjacent the crown of the feed roll but slightly removed from the knife edge, for proper guidance of the leather blank into the knife. This type of guide permits the operator to control to some extent the depth of the cut by feeding the blank in either a straight or a slightly angular direction. If the blank is fed at a small angle toward the rear of the machine, the cut will be deeper because the rear of the presser foot is closer to the knife, while if the blank is guided 'at a slight forward angle, the skive will be more shallow. When a grooving operation is to be performed, however, it is usually desired that the spacing between the edge of the blank and the groove 'remain'absolutely constant,'regardless of any sharp bends in the contour of the leather blank. I achieve these results by cutting the feed roll off immediately behind 'its crest and positioning a guide member immediately'behind the edge of the feed roll.

This guide member is equipped with a shoulder extending toward the knife. A guide finger is mounted at the rear of the grooving foot and extends downward from the grooving foot sufficiently to engage the shoulder of the guide'member and depress the guide member out of 0perative position (i.e., below the edge of the feed roll) as the finger on the grooving foot moves into operative position. 7

Referring now to FIG. 1, the machine of the invention is therein generally shown at 10. The machine is mounted on a ta'ble 12, below which is mounted a cross member 14 pivotally supportinga pair of pedals 16 and 18 on hinges 2022. The right-hand pedal 16 is "connected through a linkage 24 to the clutch control of an electric motor (not shown) which operates the rotating knife 26 and the feed roll 28 of the machine 10. The left-hand pedal 18' is connected through an operating rod 30, hinge 92 and the bowed or off set portion 94 with a presser foot operating connec tion mounted on the head 48 of the machine. This presser foot operating mechanism includes a self-locking drive connection, which drive connection will be described hereinafter. A work surface is formed by the top of left-hand cover 34 which can be pivoted about hinges 36 to expose the mechanism of the feed roll 28 and grinding wheel 84 (FIG. 2). The cover 34 is wider than mechanical considerations require in order to provide a sufficiently extensive work surface to the left of the feed roll to keep the entire blank fiat during the skiving operation. The work surface is continued by the horizontal portion 38 of the machine, and an extension 40 of the work surface projects toward the operator from the top of the front panel 42. A head-carrying arm 44 attached to the rear panel of the machine has welded to it a supporting plate 46. The supporting plate 46 supports the head 48 which is shown in detail in FIG. 2 and which is normally concealed by a head cover 50. Adjusting screws 52 and 54 protrude from the head cover 50 for the purpose of allowing adjustment of the minimum distance between the corresponding presser foot and the knife 26. The presser foot which is in the operating position (in FIG. 1, it is the front presser foot, i.e., the one providing a plane skive) is shown projected below the head cover 50 and indicated as 55 in FIG. 2. An adjusting screw 58 is provided on presser foot 56 for adjusting the inclination of the presser foot 56 with respect to the knife 26. Other controls provided are knife advancing knob 66 which permits compensation for wear of the knife, the grinding wheel operating knob 62 for sharpening the knife, and the feed roll lowering knob 64 which permits retraction of the feed roll 28 into the machine if desired.

In FIG. 2a, the work surface of the machine is once again shown at 38, with its extension 41 protruding on the right nand side in FIG. 2a and FIG. 2b, which is the front of the machine. The knife 26 is shown mounted below the work surface 38. The feed roll 28 is supported for rotation by a bracket 70, best shown in FIG. 3. This bracket 70 carries an outboard bearing for the feed roll and is, in turn, provided with a horizontal trunnion 7t). Trunnion 70 is, in turn, rockably mounted in a suitable socket in the horizontal portion of a main bracket 75, which extends from front to back of the machine. Bearings 75 and 75" support the bracket 75 for rocking movement about a horizontal axis extending fore and aft of the machine. The rear bearing 75" is adjustable by the screw 74 to move the frames or brackets 75 forwardly and rearwardly of the machine. The trunnion 70, in turn, has its left end clamped in a bracket 70", which at the lower end carries an attaching screw 64 which abuts a boss 75b depending from the rocking bracket 75. Thus by adjusting the screws 74, trunnion 70' will turn in its bearings on bracket 75 raising and lowering the outboard bearing supporting the feed roller 28, so that the outer surface of the feed roll 28 can be aligned parallel to the cylindrical portion of the knife 26, in other words, this adjustment 64 and the screws 74 are provided to locate the surface of the feed roll 28 concentric with the edge of the knife. The feed roll itself is driven by a flexible shaft 72 by suitable bearings from the main drive shaft 73, the feed roll 23 is biased upwardly against the work, and for this purpose spring 76 connects with bracket 75 and with a fixed part on the machine base in such a way as to tend to rotate the bracket 75 in a counterclockwise direction when viewed from the front of the machine. The variations in thickness in the leather have a tendency to cause some vertical movement downwardly or upwardly of the feed roll 28 due to its yieldable mounting. These variations in the position of the feed roll are due to the variations in thickness of the leather inserted between the upper surface of the feed roll and the lower edge of the presser foot 56. An adjustable stop member 78 is screw threaded in the leg of the bracket 75 abuts a lug 88 on the base frame of the machine 82 to prevent upward movement of the feed roll 28 against tension of the spring 7 6 to the point where it would touch the knife 26. The adjusting screw 64 has its inner end protruding into the boss 75b and keyed by a pin within the boss, so that the screws 64 can fix the distance between the bracket and the boss b. For this purpose, the boss 75b can have an arcuate slot.

A grinding wheel 84 is mounted on a shaft within a bearing 86 and driven by a belt drive (not shown) engaging a pulley 88 on the opposite end of the shaft. The bearing 86 is on the end of one arm of a bell crank bracket 386 which, in turn, is rockable on bearings journaled in lugs 387, and 388 integral with the housing 82. A spring 90 controlled by a stop screw 62 also connected with the bracket 3% biases the bracket 386 in the direction to move a grinding wheel 84 into engagement with the knife 26. The knife 26 can be sharpened by rotating the knob 62, so as to allow the spring to move the grinding wheel 84 against the edge of the knife 26 as it rotates. The wheel is moved away from the knife by the positive action of the screws 62.

The pedal or treadle 18 hinged to cross-member 14 by hinge 22 is hingedly attached at its rear end to the operating rod 30. The operating rod 38 is hinged at 92 and bulged out at 94 for a purpose described hereinafter. The effective length of operating rod 31! can be coarsely adjusted by connecting member 136 to an yone of holes 91 inrod 30, a fine adjustment of the length of rod 39 being provided by a screwthreaded adjustable link 93. A look nut is provided to maintain the adjustment of link 93.

Control Connection The control connection from the foot pedal 18 is transmitted through a self-locking type of mechanism or control connection, indicated generally by the reference character 1% in FIGS. 14 through 17, inclusive. This description will be confined to a general construction of the mechanism, its mounting on the mounting plate 192 and its operation, in that order. The backing plate 410 for the locking device, shown best in FIG. 16, carries on its forward sides a pair of arcuate tracks, such as 411 and 412. The particular mounting of these tracks is immaterial to the invention, but as shown each track 411 and 412 has a flange, such as 413 and 414, respectively, and these flanges are suitably secured to the backing plate 410 by screws 416 and 417 in the flange 413, and 419 and 421 in the flange 414. Preferably, the tracks 411 and 412 are arcuate portions of a circle whose center is slightly below a stub shaft, such as 423, suitably secured to the backing plate 410 by a screwthreaded connection not shown. Locknut 424 on the threads of the stub shaft 423 lock the stub shaft securely in the backing plate 410. The outer end of the shaft 423 is screwthreaded as 425.

Stub shaft 423 projects through a bearing 427 in double trigger mechanism 429 (FIG. 16). A pair of arms, which are substantially identical and indicated as 431 and 432, project in opposite directions from the double trigger mechanism 429'. The rotary mounting for the double trigger mechanism is located substantially midway between the two arms 431 and 432. Arm 431 carries an adjustable set screw 434, the upper end of which is a trigger. The set screw 434 is suitably threaded through the arm 431, and is secured in any given adjusted position by an Allen type set screw 435 threaded in a hole in the front face of the arm 431. Similarly a set screw 436 has a projecting end which forms the other trigger mechanism, and this screw is similarly mounted in the arm 43-2 and secured in adjusted position by an Allen set screw 438. Also on the front face of the double trigger mechanism 429 is a fixed lever, or lug 439, secured to the front face of the double trigger 429 by suitable screws 44!] and 441. The hole 442 in the end of the arm 439 is pin connected with the control rod 30 by a bolt, or the like, 26, so that movement of the pedal 18 and its connecting link or rod 30 will rock the double trigger 429 on the stub shaft 423. This shaft 423, also rotatably or rockably, mounts the control lever 444 on a suitable bearing surface in the aperture 445 thereof, control lever 444 has a pair of laterally projecting arms 447 and 448 which extend radially in opposite directions. It also hasan upwardly projecting arm 449 with a suitable aperture 450, which, in turn, is connected with one end of the link 108 extending to the presser foot operating mechanism hereinafter described. Each of the arms 447 and 448 carry articulated grippers generally indicated as 452.

- Since both are substantially identical only one of the as at 453. The opposite side surfaces of the slot 453 have jaw-like devices 454 and 455 formed by pins which are cylindrical, and which are secured in cylindrical sockets in the lower surface of the slot 453. Preferably, the cylindrical pins 454 and 455 have a press fit in these sockets, and may be brazed or otherwise firmly secured.

It will be noted that the jaw-like devices 454 and 455 are not exactly opposite one another, and that the pin or jaw-like device'455 is slightly below the jaw-like device 454. The purpose of so arranging the jaw-like devices with their cylindrical surfaces offset from one another in this manner will be explained hereinafter in the operation of the self-locking mechanism. Preferably, the cylindrical surfaces of the pins 454 and 455 are hardened, so as to resistwear.

The gripper 452 has a projecting lug 456 'with a rectilinear slot 457. This slot forms a part of the articulated mounting on the control lever 444, which mounting includes a block, such as 459, apertured at 460 to receive a screw 461 with a washer 462. The end of the control arm 444 has a threaded aperture 464 for receiving the screw 461. The articulated mounting for the gripper 452 is assembled by placing the block 459 within the elongated slot 457 and then inserting the screw 461 into the control arm, until the washer 462 abuts the outer surface of both the block 459 and the lug 456. Block 459 is smaller than the slot ,457, so that gripper 452 can slide lengthwise of arm 447. Also since the block 459 can pivot on the screw 461, the gripper 452 can also pivot as well as slide. On the control arm 447 and on arm 44% are similar stops, which are identical in construction. These stops are indicated as 465, and both have their lower surface socketed to receive a coil spring 466. The upper face of both grippers 452 have sockets 468, whichfwill receive the opposite end of the coil spring 466.

' Inthe assembled position of the control arm and grippers withthe mounting plate, the grippers 452 will have their jaw-like devices 454 and 455 straddling the arcuate tracks 411 and 412, respectively, and this control arm is secured in this position by suitable nut threaded on the threads 425 on the end of the stub shaft 423.

' FIG. 15 illustrates a back view ofthe backing plate.

On this reverseside, the backing plate has a spacer 470 secured to the back face of the backing plate by screws 471 and 472. The left end of the backing plate has a slope, or is inclined to the vertical as at 474, forming a lug which is apertured at 475 (see FIG. 17.). The spacer 470 is the same thickness as flanges 180 are deep as shown in FIG. 2a, and the inclined portion 474 of about the same angle with respect to the mounting plate 102, so that the inclined'edge 474 overlaps the flange 180 'and can be secured thereto by a suitable screw, such as 476, threaded into the flange 180. The holes 471 and 472 in the spacer 470 are threaded, so that the spacer may be secured to the backing plate 410 by screws projecting through the backing plate 410 into and threadingly engaging the holes 471 and 472. Spacer 470 is secured to the rear face of the mounting plate 102 by a bolt and nut, or the like, 478 and 479. This nut 479 may be re- 7 V ceived in a socket in the face 102, so that the back face Operation of Control Turning now to FIG. 18, the position of the parts of the control are shown in their extreme position with the rod 108 to the right. This position will correspond with the position of the pressor 'foot 56 in FIG. 2. As described, thepusher or rod 30 is connected directly with the trigger mechanism 429, which is pivoted on the stub shaft 423 together with the arm 449. The position of the parts in FIG. 18 is one indicating the operation of the mechanism after the rod 30 has rotated the trigger mechanism 429, and with it the control lever 449 in 'a clockwise direction to an extreme right hand position, during this movement of the control rod 30 upwardly, trigger mechanism 429 holds gripper 452 on the left side of the control arm 447 released as the screw 429 forces the trigger 434 under the end of the gripper 452 to rock the gripper 452 in a counter-clockwise direction as view in FIG. 18, so that the upper surface of the gripper 452 is in contact with the left hand stop 465. Movement of the left hand gripper 452 by the set screw 434 into contact with the stop 465 rotates the gripper 452 sufficient to increase the spacing between jaws 455 and 454 thereon, so as to release their grip on the arcuate track 411, on the other hand the clockwise rotation of the trigger mechanism 429 causes the gripper 452 to contact stop 465, and thus move the arm 449 in a clockwise direction with the movement of the trigger mechanism 429 thereby forcing the control rod 108 to the right. 7

During this movement of the control rod 108 and control arm 449 to the right, screw 436 has released its pres sure on the right hand gripper 452 allowing the spring 466 to pivot the right hand gripper 452 away from the stop 465. Because of the displaced relationship between the inner jaw 454 and the outer jaw 455 of the right hand gripper however, any frictional resistance to clockwise movement of these jaw-like devices along the track 412 releases them from gripping action because it tends to rotate the gripper 452 in a clockwise direction. When the control arm 449 has reached its full extreme right handposition, the parts presumably come to rest in which the right hand grip under the action of the spring 466 moves the jaw-like devices 454 and 455 into firm engagement with opposite sides of the track 412. Any force on the control arm 449 tending to move the control arm in a counterclockwise direction from this position will apply a force to the right hand gripper 452 at its outer end or its articulated mounting to the arm 448. Such a force of course, will tend to rotate the. gripper 452 in a counterclockwise direction, but since the jaw-like devices 454 and 455 are already gripping the arcuate track 412,

the gripper 452 will not only resist this counterclockwise rotation, but also resist any sliding movement along the track 412 for the simple reason that the rotational or unbalanced forc e on the gripper 452 imposed by the arm 448 and through its connection with the gripper will merely cause the jaw-like devices to grip the track 412 more firmly. Consequently, in the position of the part shown in FIG. 18 with the trigger mechanism disengaged from the right hand gripper 452, the linkage control system'from link 30 to link 10S cannot beimoved in the reverse direction. In other words, link 30 can release the control lever for movement by operation of the trigger mechanism, but the control rod 108 cannot move unless the locking action of the self-locking -drive connection is released to allow it to move. 7

Turning now to FIG. 19, the position of the parts is indicated in which the control rod 30 has been moved to unlock the trigger mechanism and the grippers so as to move the control arm 449 in a counterclockwise direction. In other words, a very small movement of the control rod 30 downwardly disengages the screw 434 on the left hand side and engages the screw 436 on the right hand side with its gripper forcing the right hand gripper 452 toward its stop 465, and rotating the gripper 452 in a clockwise direction so as to increase the spacing be- 9 tween pins 454 and 455 relative to the track 412, simultaneously, the screw 434 releases its pressure on the left hand gripper 452 allowing the spring 466 to move the gripper in a clockwise direction so as to bring the jaw-like devices formed by pins 454 and 455 of this gripper into engagement with the left hand track 411. Of course, as the control rod 30 moves downwardly rotating the control arm 449 through the connection 436, 452 and stop 465, the left hand gripper 452 remains in this position with the jaw-like devices formed by the pins thereof forced into contact with the opposite sides of track 411 by the spring 466. Anywhere that the control rod stops rotating the control arm or lever 449, left hand gripper 452 would immediately come into action to resist any movement of the control arm or lever 449 in the opposite direction (clockwise) so long as the screw 434 is out of contact with the gripper 452. The trigger mechanism, therefore, is the release which allows movement of the control lever 449, and if both screws 434 and 436 are out of engagement with their respective gripper elements, the control lever 449 would be locked in a fixed position against movement in any direction around the stub shaft 423. It will be understood from the above description that no movement of the control arm 449 can occur unless the grippers are triggered, and the grippers will not be triggered unless one or the other of the trigger members and screws 434 or 436 are moved into contact with a gripper by the control rod 30. Consequently, control rod 30 and pedal 18 have a self-locking drive connection to control the presser feet, and no amount of pressure on the Presser feet can affect the pedal so long as the trigger mechanism is in a neutral position. In practice, the clearance between stop 465 and grippers 452 are maintained very close by adjustment of the screws 434 and 436, and this adjustment can be so precise that no lost motion can be felt in the pedal mechanism during movement of the presser feet. The articulated mounting of the grippers, with respect to the control lever 449, will accommodate any slight eccentricity between the stub shaft 423 and the inner and outer surfaces of the arcuate tracks, so that the device is completely flexible and operative regardless of the precise location of these elements. However, it has been found that some slight eccentricity is altogether desirable from an operational standpoint. When this is provided, the operation of the device is improved to some extent, and the gripper mountings, which are articulated to swing so each gripper can swing on centers displaced right and left of the control lever pivot, provides for compensation for the eccentricity. It should also be noted that corresponding pins in each gripper, that is the inner pins 454, are offset from a line extending through the other pair of pins 455, and that this ofiset is provided to make the grippers a one way lock. The same action could be provided by a single gripper and a single track with a trigger mechanism which moved the gripper end in opposite directions, but for the purposes here described of obtaining precise control the two gripper type of selflocking control is preferred.

Presser Foot Mechanism Control rod 12% connects with a control lever of 114 for operating the presser foot mechanism hereinafter described. The connection may be made at 112, if desired. Actuating arm 114 is pivotally mounted on the head mounting plate 102 by a shaft 116. A plate 118 is spacedly mounted to the left of the lower portion of acuating arm 114 (i.e., in front of arm 114 as seen in FIG. 2) so as to pivot together with arm 114 about shaft 116. A pair of hinge pins 120, 121 and a pair of latch pins 122, 123 extend between plate 118 and arm 114. Guide arms 124-, 126 are hingedly supported between plate 118 and arm 114 by hinge pins 120 and 121, respectively, and latching wings 125, 130 which are pivotally attached to guide arms 124, 126 by shafts 132, 134 have hook-shaped extensions 136, 138 which tend to engage the latching a be sufficient to achieve the same result.

pins 122, 123 when the hooks 136, 138 are pulled toward arm 114 by spring 1419. Stop members 142, 144 secured to opposite edges of plate 118 and positioned between guide arms 124, 126 and plate 118 have shoulders 146, 148 (FIG. 9) extending underneath guide arms 124 and 126, prevent movement of guide arms 124, 126 below a predetermined position when the latching wings 128 or 130 are unlatched.

The outer ends of guide arms 124, 126 are generally U-shaped, the U having a short upper leg and a longer lower leg 152 enclosing between them a recess 154. Rolls 156, 158 mounted on slides 160, 162 by shafts 164, 166 are engaged by the legs 150, 152 for movement up and down in the V-shaped rails 168 (FIGS. 4 and 9) formed in the central rail block 170 and the outer rail blocks 172, 173. The central rail block 170 is fixedly attached to the head mounting plate 102. The outer rail blocks 172, 173 are movably mounted on the head mounting plate by means of screws 174 inserted in slots 176. The outer rail blocks 172, 173 can be tightened against the slides and 162, respectively, by tightening screws 178 threaded into flanges 180 of the head mounting plate 102 parallelling the rail blocks 172 and 173. Then, when tight fits between slides 160, 162, rail blocks and rail blocks 172, 173 have been obtained, screws 174 can be tightened to hold the rail blocks 172, 173 in place.

Let us suppose now that the forward presser foot '56 is in the working position, and that the rear presser foot 184 is in the retracted position, as shown in FIG- URE 2. If the toe end 186 of pedal 18 is now depressed, operating rod 30 will be moved in a downward direction, imparting a counterclockwise movement to double trigger mechanism 429 releasing the lock of gripper 452 with track 412 and by contact with the stop 465 on the control lever arm 447 rotate the control lever 449 in a counterclockwise direction. This will result in linkage rod 108 being pulled to the left, which in turn will impart a counterclockwise movement to actuating arm 114. At the beginning of this motion, latching wing 130 mounted on guide arm 126 is hooked to latching pin 123, so that guide arm 126 is rigidly held fixed in a position indicated in FIG. 2a on actuating arm 114. The counterclockwise movement of arm 114 will therefore result in moving upward the roller 158 positioned in recess 154. Since roller 158 is mounted on slide 162, this motion will cause slide 162 to travel upward, retracting presser foot 56 out of the working position. When slide 162 has been raised sufficiently to withdraw presser foot 56 out of the path of presser foot 184, the upper surface 191} of latching Wing 130 comes to butt against stationary roller 192 mounted on rail block 170. Further counterclockwise motion of actuating arm 114 causes a clockwise torque to be imposed on latching wing 130, which in turn overcomes the force of spring 140 and causes hook 138 to becomes disengaged from its latching pin 122. At the same time, the inner surface 194 of leg 152 of arm 126 butts against a stationary pin 196 mounted on the forward rail block 172. Inasmuch as latching wing 130 is now unlatched, further counterclockwise movement of arm 114 causes guide arm 126 to pivot around its pivot pin 121 in a clockwise direction. During this clockwise motion of guide arm 126, the force exerted by [pin 196 on surface 194 of leg 152 overcomes the bias of spring 19% extending between the top of actuating arm 114 and the outer end of leg 15% of guide arm 126. It will be seen that spring 198 tends to pull guide arm 126 toward its latched position. Strictly speaking, the spring 193 is not really necessary because the torque exerted by spring 1419 connecting latching wings 128 and 13% would It may be, however, preferably to provide the spring 198 in order to assure more positive action of the mechanism. After latching wing 139 has become unlatched, the clockwise movement of guide arm 126 compensates for the counterclockwise movement of actuating arm 114, so that there will be no further upward movement of slide 162 after 126 is firmly held between pin 196 and flange 148 so that it cannot move imder the influence of vibrationor jarring of the machine. Consequently, the slide 162 is also held firmly in the retracted position.

Turning now to the operation of the mechanism associated with slide 169 during the same counterclockwise movement of actuating arm 114 which has been discussed above, it will be seen that this mechanism started out in the position shown in FIG. 2 wherein slide 160 and presser foot 184 are in the retracted position, the guide arm 124 is firmly held between pin 2% mounted on the rear rail block 172 and flange 146 of stop member 142. The latching wing 128'in this condition is in the unlatched position, where it is held by roll 202 mounted on rail' block 170. When the counterclockwise motion of actuating arm 114 commences, the spring 204 extending between the top of leg 150 of guide arm 124 and the top of'actuating arm 114 pulls the guide arm 124 in a clockwise direction around its pivot pin 120. As in the case ofspring 198, spring 204 is not really necessary because spring 140 would have the same effect, but

it is preferable to provide a spring 204 in order to assure a more positive action of the mechanism. During the rotation of guide arm 124 about its pivot pin 120, the slide 169 does not move, as the clockwise motion of arm 124 is compensated by the counterclockwise motion of arm 114. When the actuating arm 114 has reached an approximately vertical position, the motion of guide arm 124, combined with the effect of roller 202 has carried the latching wing 128 into a position where its hook 136 can reach and engage its latching pin 122 under the pull of spring 140. This vertical position of arm 112 is the position in which slide 162 has'just reached its fully retracted position, so that the way is now clear to bring presser foot 184 into its working position. Since the latching of latching wing 128 results in rigidly fastening guide arm 124 to actuating arm 114, the remainder of the counterclockwise movement of arm 114 results in a counterclockwise movement of guide arm 124 together with actuating arm 114 about pivot point' 116. This in turn results in downward movement of the roller 156 under the influence of leg 150 of guide arm 124. Inasmuch as roller 156 is mounted on slide 160, this motion of roller 156 results in sliding the slide 160 down- 12 tion is described in more detail in FIGS. 7 aud -8 which will be discussed hereafter;

A head carrying arm 44 is rigidly mounted to the rear of the casing of the machine 10 and extends upwardly and forwardly above the work surface 38, terminating in a vertical supporting plate 46 (see FIGS. 3 and 4) rigidly attached to arm 44. The head mounting plate.102 is held to the supporting plate 46 by a pair of mounting screws 226. Set screws 228 threaded into supporting plate 46 and butting against the head mounting plate 162 at 230 permit adjustment of the head mounting plate 102 with respect to supporting plate 4-6. A pin 232 extends to the right from actuating arm 114 and fixed pin 238 is mounted on the supporting plate 46. The pins are connected by a spring 236 which biases arm 1 14 into either its farthest clockwise or its farthest counterclockwise position so as to hold the presser feet firmly in their working position. Of course, any appropriate detent means may be used in lieu of the toggle spring.

It will be seen from'FIGS. 3, 4 and 5 that the adjusting screws 52, 54 are mounted not directly above the slides 162, 160 with which they are associated, but rather to the right thereof on blocks 240, 242 which in turn are mounted on the slides 162, 160. Thevcenter of adjusting screws 52, 54 is located immediately above the upper edge of head mounting plate 102. It will be seen from FIG. 5 that head mounting plate 102 has kerfs 2'44, 246 formed therein. The lower ends of screws 52,54 butt against these kerfs 244, 246. Inasmuch as the screws 52, 54 are mounted in blocks 240, 242, which in turn are mounted on slides 162, 160, the slides 162,

ward so as to bring presser foot 184 into the working position. a

Referring now to FIG. 3, the work surface of the machine is once again shown at 38. The knife 26 is 'driven by a shaft 210, the axial position of which can be adjusted by a gear mechanism 212 on a threaded thrust bearing operable by knob 60 (FIG. 1). The feed roll 28 is adapted to rotate in a clockwise direction in FIG. 3 so as to feed leather blanks from the left-hand portion 34 of the work surface, past the knife 26, and 'onto the portion 38 of the work surface. A guide member 214 having an upwardly extending protuberance 216 and ahorizontally extending shoulder 2-18 (see FIG. 7) is mounted on the end of a leaf spring 22! attached to the work surface 34 by screws 222. The guide member 214 is positioned immediately behind the rear edge of the 160 can move downwardly only until the lower end of the adjusting screw corresponding to the moving slide hits the kerf in head mounting plate 102 associated therewith. 'The screws52, 54 therefore permit adjustment of the height with respect to the knife 26, in the working position, of the'presser foot associated therewith. Additional recessed set screws 248; 256 are also provided in blocks 240, 242 for cooperation with stops 252, 254 formed in head mounting plate 102. The operation of set screws 248, 250 is identical to that of adjusting screws 52, 54 and they are provided for the purpose of establishing a limit for the effectiveness of the adjustment of screws 52, 54. The set screws 248, 256 are so set at the factory that they will not permit lowering of the slides with which they are associated to a point where the presser foot associated with the set screw would touch the feed roll. Thus, height of the working position of each presser foot is controlled by the adjustment screw corresponding thereto, with the minimum being determined by the safety set screw associated therewith.

In order to prevent mis-adjustment of adjustment screws 52, 54 due to vibration of the machine or accidental contact of the operator with the screw, several devices may be used. FIG. 5 shows two such devices. Adjustment screw 54 is shown held in place by a heavy spring 256 extending between the lower surface 258 of screw 54 and the upper; surface 260 of block 242. The friction of the ends of spring 256 against the surfaces 258 and 269 is suflicient to prevent screw 54 from accifeed roll 28 as best seen in FIG. 2. The spring 220 is I guide finger 224 of presser foot 184 (FIGS. 7, 8) engages shoulder 218 and pushes guide member 214 downward so as to .lower the protuberance 216 below the level of work surface 34 (see FIG. 8). This lowering operadentally turning, but insuflicient to prevent the operator from turning the screw by getting a solid grip thereon.

An alternative device for preventing accidental misadjustment of the adjusting screw is a simple lock nut 262 shown in connection with adjusting screw 52 in FIG. 5. This arrangement makes the adjusting screw easier to turn, but presents the danger of disturbing a critical adjustment when the lock nut is turned to locking position.

Turning now to FIGS. 7 and 8, the device shown therein is the grooving presser foot, FIG. 7 being a lefthand perspective view thereof in partly retracted position, and FIG. 8 being a right-hand perspective View thereof in the working position. The presser foot 184 is pivotally mounted on a bracket 264 which is mounted on slide 160 by a screw 266. The presser foot 184. is biased for counterclockwise movement in FIG. 7 about pivot pin 268'by a spring 276 A tab 272 of presser foot 184 extends into the path of an adjusting screw 276 threaded into a flange 274 formed on bracket 264. The adjusting screw 276 is provided with a lock nut 278. The extremity 280 of adjusting screw 276 butts against tab 272. Thus, when adjusting screw 276 is advanced in the threaded flange 274, it pushes the tab 272, and with it the presser foot 1'84, forward so as to cause presser foot 184 to move in a clockwise direction about pivot pin 268. In this manner, the angle between the presser foot 184 and the knife 26 can be adjusted. In order to make the groove in the leather blank, a grooving finger 282 is provided. Finger 282 is slidably mounted in a notch 284 in the presser foot 184. A set screw 286 is provided in the rear of the presser foot 184 for maintaining the vertical adjustment of the grooving finger 284. A guiding finger 224 is provided at the rear end of presser foot 184 for cooperation with the shoulder 288 of guide member 214 in a manner previously described in connection with FIG. 3. When presser foot 184 is in its working position, the guiding protuberance 216 of guide member 214 is depressed below the crest of feed roll 28, and the forward surface 288 of guide finger 224 assumes the role of guide member. It will be noted from an examination of FIGS. 7 and 8 that the bottom surface 290 of presser foot 184 is inclined so that its left-hand side is lower than its right. This is done for the purpose of guiding the leather blank 291 (FIG. 10) down into the knife, the actual depth of cutting being determined by the height of the (lower) lefthand edge of surface 299 with respect to the knife 26, as shown most clearly in FIG. 10.

Occasionally, it may be desirable to skive, in the same piece of leather, along, fiat bevel as well as a shorter but equally flat bevel which does not remove as much of the thickness of the leather blank at its edge as the long fiat bevel does. In such a case, I may provide an adjustable gauge as shown in FIG. 13. This device consists of a tapered plate 360 lying generally in the plane of the work surface 38, in which a recess 302 is formed directly underneath plate 300. A shoulder 304 on the underside of plate 300 serves as a guide for the leather blank in the same manner as guide member 216 previously discussed herein. A supporting arm 3116 is slidably mounted in a holder 308 to which it can be fastened by tightening screw 310 riding in slot 312. Supporting arm 3416 supports plate 300 at its end, so that plate 300, and with it shoulder 304, is movable toward and away from the operator. Movement is achieved by manipulating the handle portion 314 of supporting arm 306.

If it is now desired to make a long bevel, the operator passes the leather blank over plate 3430 so that the edge of the blank will be guided by guide member 216 in the manner previously described. When it is desired to make a short bevel, however, the leading end of the leather blank is pushed down by the operator so that the blank will slide under the plate 300, whereupon its edge will be guided by the shoulder 364 which is positioned more or less in front of guide member 216. Thus, a lesser width of the blank will come into contact with the knife 26, and the resulting skive will be shorter than that achieved if the blank is passed over plate 300.

Going back to FIG. 2b, the operating rod was seen to be hinged at 92. The housing 82' of the machine can be tilted backward about hinges 292 for access to the mechanism underneath the working surface 38. If this is done, the upper portion 94 of operating rod 30 will also tilt backward about hinge 92. The shape of portion 94 is so calculated that it vw'll clear any rearwardly extending parts of the machine during the backward tilting motion. Inasmuch as the hinges 292 and 92 are slightly spaced from one another, tilting of the machine will result in a slight pivotal motion of lever 114. This pivotal motion,

however, is not enough to push the head mechanism past its extreme clockwise position, so that it is unnecessary to disconnect the operating rod 30 from trigger mechanism 429 when it is desired to tilt the machine backward for servicing of the mechanisms on its underside.

Operation If it is assumed that the head assembly is in the position shown in FIG. 2 and that it is desired to bring the grooving foot 184 into position adjacent the knife, the operation will take place as follows: The operator depresses the treadle 18 so that the toe end 186 of treadle 13 moves downward. This causes operating rod 30 to move downward, which in turn causes trigger mechanism 429 to move in a counterclockwise direction. This causes arm 449 to move to the left, carrying with it linkage rod 108. Linkage rod 168 in turn moves actuating arm 114 in a counterclockwise direction about pivot 116. Since guide mm 126 is at this moment latched to actuating arm 114, the counterclockwise movement of actuating arm 114 will cause portion 152 of guide arm 126 to push roller 158, and with it slide 162 and presser foot 56, upward. When actuating arm 114 has reached the vertical position, latching wing contacts roller 192 while at the same time, the hook of latching wing 128 becomes engaged with'pin 122 on actuating arm 114. As the counterclockwise movement of actuating arm 114 continues, the roller 192 butling against latching wing 130 causes latching wing 130 to become disengaged from pin 123 on actuating arm 114, and the upward movement of slide 162 ceases. At the same time, latching wing 128 having become hooked to pin 122, guide arm 124 is rigidly connected to actuating arm 114, so that further counterclockwise movement of actuating arm 114 will result in portion of guide arm 124 pushing roller 156 downward. This in turn causes slide 1611, and with it presser foot 184, to move downward into'a position adjacent the knife. The downward movement of presser foot 184, as well as the movement of the other parts of the mechanism, is eventually stopped by adjusting screw 54 butting against shoulder 246 of mounting plate 102. The reverse operation is accomplished similarly by depressing the free end of treadle 18.

Detailed Description of Modification In the modified form as shown in FIG. 20, the head mechanism is the same structurally except for minor differences to that shown in FIG. 2, and corresponding parts thereof will be given the same reference character with 5011 added. Since the parts of the head mechanism correspond with those already described and the angle between the slides 6611 and 662 is the same as between the slides 160 and 162, a detailed description of the mounting will be omitted, and this description confined to the diiferences between the structure shown in FIG. 20 from that shown in FIG. 2.

As will be readily recognized from an inspection of FIG. 20 in this modification, the head mechanism has been rotated through an angle of approximately 30 de grees or so, so that the slide 662 of the forward presser foot is substantially vertical, while the slide 660 of the rear presser foot is inclined to a greater extent with the vertical. This change causes the slide 669 for the rear presser foot to occupy a position between the mounting plate 410 for the self-locking mechanism and the plate 46 of the head of the machine. However sufficient clearance is provided between for the proper operation of the slide 660. Further in this modification, each slide, such as the slide 662 for example, has a slot therein with closed ends, such as 664. Slide 666 also has a similar slot 658. Slot 664 receives a pin, such as 642, mounted in the backing plate for the head mechanism 602, and similarly slot 658 in slide 666 receives a pin, such as 650, also mounted in the backing plate 692. The pins and slots will limit the movement of the slides in the downward direction, and so that this movement will be adjustable and can be preset each slide has an adjusting screw. Adjusting screw 652 in slide 662 projects into threaded engagement with the end of the slide and into engagement withthe pin in the slot. Slide 660 also has an adjustable screw 654 which projects into threaded engagement with the end of the slide 660 and into the slot for engagement with the pin.

Obviously, adjustment of the screws 652 and 654 will limit the downward movement of the slides- This modification differs somewhat in the construction of the presser feet which are attached to the end of slides by suitablescrews, these presser feet are shown more in detail in FIGS. 21 through 27. Turning now to FIGS. 21 through 23, the front presser foot mounted on the front slide 662 has a fixed cmier and a movable carrier. The fixed carrier, thus illustrated in FIG. 22, has a tongue 720 projecting from its rear side and apertured at 721 to receive the screw which attaches the tongue in the groove 720A at the bottom of the slide 662, thus providing a tongue and groove connection between the fixed carrier and the slide 662 which has a flush'surface coplanar with the front exterior surface of the slide, so as not to interfere with the mechanism of the head as it moves upwardly and downwardly. The fixed carrier is in turn rabbeted on its rear side as at 72 4, which slot is dimensioned to slidably receive the tongue 726 of the movable carrier 725, the tongue 726 and slot 724 are so dimensioned that when the tongue is in the slot there is no part of the tongue projecting from the back surface of the fixed carrier 720. On the front face of the fixed carrier is a boss 728 with an inclined threaded passage 729 receiving the screw 730. As will be noted from an inspection of FIG. 22, the screw 730 projects from one wall of a slot 731 in a flange 732 .at one edge of the slot 724. The slot 731 has an upwardly facing flange 732 which operates as a limit stop for the movable carrier in a manner hereinafter described. a

On the side of the tongue 726 of the slide carrier shown in FIG. 23 is a lug 734 with an inclined top face 735 and a flat bottom face 736. Lug. 734 is received and is movable withinthe slot 731, and the tongue 726 is slidable in the slot 24. Integral with the inner face of the tongue 726, and forming an extension thereof, is a plate 738. The plate near its outer end mounts a fixed pivot pin 746 as shown best in FIG. '21, and this pin forms the pivot for the front presser foot 742. A lug 744 projects downwardly from the presser foot on one side of the pivot 740, and this lug performs the function as does the lug 224' illustrated in FIG. 7 and FIG. 8. The back face of the presser foot 742 is grooved at 745 to receive a grooving pin 746 which projects from its lower surface. The pin is secured in'the groove 745 by a set screw 748 which is threaded through the side of the presser foot 742 and projects into the groove 745.

On the front face of the plate 738 of the slide carrier 726 is atboss 750 which is threaded to receive an adjusts ing screw 751. "The end of the screw 751 projects from the bottom of the boss into engagement with a pin 753 which projects from the presser foot through the notch 754 in the plate 738.

j Operation 7 When. the parts of forward presser foot are assembled,

they are held in assembled relation by screw 756 in threaded engagement with a tapped hole in tongue 726 and by a spring 755 secured at one end to the screw 756 on the front of the fixed carrier and hooked around the pin 753 behind the end of the adjusting screw 751. This retains the presser foot on its pivot 740. The slidable carrier is held in the slot of the fixed carrier, against removal therefrom, by the screw holding the tongue 720 of the'fixed carrier in the groove in the slide 662, so that the .slide carrier 725 can move only vertically against, or with, the spring 7 55, and its movement is limited by engagement between the inclined face 735 and the adjusting screw 730 in one direction, or the engagement of the face 736 of the lug 734 with the fixed stop 732 in the other direction. To adjust the pressure foot so that it cannot come in enlgagement with the knife of the machine the following steps are generally followed: In the first place the screw 652 is adjusted downwardly to raise the slide 662, and then the screw 73%) is rotated forcing the lug 734 against the stop face 732. With the parts in this position, the upper screw 652 is then backed ofi until there isv just sufiicient clearance to prevent the presser foot 742 from engaging with the knife. Screw 652 is then looked in this position so that the slide 662 can never be lowered beyond this point. After this preliminary adjustment any further vertical adjustment of the presser foot 742 is accomplished by the screw 730. After this adjustment is set, screw 73%) is locked by its lock nut 795.

Angular adjustment of the presser foot 742' is independently adjusted by the operation of the thumb screw 751, which bears against the pin 753 projecting through the slots 754. Right-hand. rotation of the screw 751 causes the pin 753 to be moved downwardly tilting the presser foot 742 in'a direction to lengthen the skive. Left-hand rotation of the thumb screw 751 backs 01f the screw so as to allow the spring 755 to move the presser foot 742 upwardly around itspivot 740 so as to shorten the skive, in other words increase the angle of the skive.

So far. the description has been limited to the detail construction of the right or forward presser foot. Turning now to the left presser foot the construction of which is shown in FIGS. 24 through 27, in thisconstruction the fixed carrier is shown in a front perspective view in FIG. 24. Referring specifically to the construction herein shown, the carrier-760 has an angular projecting tongue 761'integral with the body of the carrier 760. The tongue the front face of the fixed carrier at 767 angularly downwardly and opens at the upper end of the slot 763 at a point 768. Tapped hole 767 receives a threaded thumb screw 769.

. The slot 763 receives the guide 776 of the slide carrier generally indicated at 775. Guide 770 has a tapped hole 771 extending from one side to the other. On the front face of the guide 770 is a carrier plate 772 which mounts a fixed pin 776 projecting horizontally from the vertical .face of the carrier plate 772 adjacent a lower corner thereof. The presser foot 780'has a small hole extending from one face thereof to the other and indicated at 781, the hole 7 81 in turn receives the pin 776 to form a hinged mounting for the presser foot 780 on the plate 772 of the carrier. On the upper surface or edge of the presser foot 7 and more or less opposite the hole 781 is a projecting, angularly directed 111g 7 84 which carries the spring anchor pin 785, all is shown in FIG. 27. 7 Referring again to FIG. 24, the purpose of the tapped hole 771' becomes apparent, because as it appears in FIG. 24, the thumb screw 788 is threadedly engaged in the hole 771 of the Operation' The mechanism, just'described, whichfonns the back presser foot can be' operated as hereinafter described. While the machine is inoperative, presser foot 780 is lowered into position, and by operation of the thumb screw 769 in a right-hand direction the movable carrier 775 is lowered to its maximum. The operation of the thumb screw 76? in a right-hand direction causes the thumb screw end to force the movable guide 770 downwardly against the tension of the spring 790, and when the movement of the guide we stops due to contact between the bottom of the thumb screw 738 and the slots 764 and 765, this is the maximum distance that the guide can be moved downwardly by the thumb screw. At this point, the adjusting screw 654- is so positioned that its contact with the pin prevents the lower surface of the presser foot 780 from contacting the knife. Screw 654 is then looked in position, and when so adjusted, contact between the presser foot and the knife 26 by operation of the screw 769 is prevented, so that any time during operation of the machine, this screw may be safely adjusted without fear of damaging the knife 26. Angular adjustment of the presser foot 784 is controlled by the thumb screw 788, right-hand rotation of thumb screw 788 forces lug S in a direction to increase the angle of the skive by pivoting the presser foot 789 around the pin 776 against the tension of the spring 799'. Reverse rotation of the thumb screw 78% allows the spring to rotate the presser foot 78b in the opposite direction to steepen the angle of the skive.

In all other respects, the modification disclosed in FIG. 20 operates exactly the same as the modification shown in FIG. 2, consequently, this detailed description of the structure and the operation has been limited to the differences which permit the angular relationship of the slides with the machine as shown in FIG. 20, the sole advantage, it is believed, of the structure shown in FIG. 20 over that in FIG. 2 is a more convenient positioning of the parts from the operators viewpoint. As will be readily appreciated, the head does not project as far forward on the machine, eliminating this portion as a hazard to hand operation and as an obstruction to visible observation of the work operation by the operator.

The constructions above described in detail will fulfill all of the objects of the instant invention, but it is contemplated that other modifications will occur to those skilled in the art which come within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. In a skiving machine having a knife and a feed roll for feeding a blank to be out toward said knife, the improvement comprising a plurality of presser feet mounted for reciprocation in a flat plane and selectively movable into and out of a cooperative position with said knife and feed roll.

2. In a skiving machine according to claim 1, the improvement comprising each of said presser feet being mounted on an individual movable slide member at an angle to each other and means for reciprocating said slide members. I

3. In a skiving machine having a feed roll and a knife, the improvement comprising a plurality of presser feet which can be selectively moved into and out of a working position adjacent said knife, a plurality of sli-dably mounted presser-footcarrying slide members mounted to reciprocate in one plane at an angle to each other, and means operative to move one of said slide members away from said knife and another toward said knife.

4. In a skiving machine having a feed roll and a knife, the improvement comprising a plurality of presser feet which can be selectively moved into and out of a working position adjacent said knife, a plurality of slidably mounted presser-foot-carrying slide members mounted at an angle to each other, and means operative to move one of said slide members away from said knife and another toward said knife, said last-named means comprising a pivotally mounted actuating member and a plurality of guide members hinged to said actuating member for moving said slide members.

5. In a skiving machine having a feed roll and a knife,

the improvement comprising a plurality of presser feet which can be selectively moved into and out of a working position adjacent said knife, a head mechanism having a plurality of slidably mounted presser-foot-carryin g slide members mounted at an angle to each other, and means operative to move one of said slide members away from said knife while sliding another toward said knife, and foot-operated linkage means for operating said lever means, said lever means comprising a pivotally mounted actuating plate, a plurality of guide pieces hinged tosaid actuating plate for moving said slide members up and down, a latch member mounted on each of said guide pieces, means for latching said latch members to said actuating plate, and means for selectively releasing said latch members when the corresponding slide member is moved up.

6. In a skiving machine having a feed roll and a knife, the improvement comprising a plurality of presser feet which can be selectively moved into and out of a working position adjacent said knife, a head mechanism having a plurality of slidably mounted presser-foot-carrying slide members mounted at an angle to each other, and means operative to move one of said slide members away from said knife while sliding another toward said knife, at least one of said slide members having an adjustable stop member cooperating with a stationary part of the machine for preventing movement of said slide member beyond a pre-settable point.

7. The device of claim 6, at least one of said slide members further having a safety stop member for rendering ineffective any adjustment of said adjustable stop mem bers for movement below a predetermined point.

8. In a skiving machine having a feed roll, a knife, and a presser foot movable into and out of a working position adjacent said knife, the improvement comprising a guide member mounted for movement adjacent said feed roll for guiding an edge of a blank to be skived, a presser foot adapted to move said guide member out of operative position when said presser foot is moved into working position and a guide member on said presser foot operative to replace the first said guide member.

9. In a skiving machine having a housing mounted on a table and containing mechanism accessible only fiom the underside of said housing, a head assembly fixed with respect to said housing, control means fixed with respect to said table, and an operating rod connecting said control means to said head assembly, the improvement comprising said housing Ibeing hinged with respect to said table for movement so as to expose said mechanism and said operating rod being hinged near the hinge of said housing.

10. In a skiving machine having a feed roll and a knife, the improvement comprising a plurality of presser feet which can be selectively moved into and out of a working position adjacent said knife, a head mechanism having a plurality of slidably mounted presser-foot-carrying slide members mounted at an angle to each other, and means operative to move one of said slide members away from said knife and to move another toward said knife, and linkage means for operating said last-named means, said linkage means being hinged so as to allow tilting movement of said machine without disconnection of said linkage.

11. A skiving machine comprising a knife, a pair of presser feet, means for moving said presser feet into and out of a working position adjacent said knife, an actuating arm, and releasable latch means between said actuating arm and said presser foot moving means for substantially preventing movement of one of said presser feet toward working position until the other has been moved substantially fully out of working position.

12. In a skiving machine, a knife, a pair of presser eet and means for moving said presser feet into and out of a working position adjacent said knife, said means being inoperative to move the presser foot associated 

